Improvement in electric lamps



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C. F. BRUSH. Electric-Lamp.

Patented Sept. 2,1879.

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G. F. BRUSH. Electric-Lamp.

No. 219,209. Patented Sept. 2,1879.

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Patented Sept. 2,1879.

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N.FEYERS, PHOTO-LITHQGRAPHER, WASHINGTON, o C.

UNITED STATES PATENT OEEICE.

oEAnLEs E. EEUsE, or cLEvELAND,` onto.

IMPROVEMENT IN ELECTRIC LAIVIPS.

Specilication forming' part of Letters Patent No. 219,209, dated September 2, 1879 application iiled May 16, 1879.

To all fulzom it muy concern Be it known that I, GHARLEs F. BRUSH, of Cleveland, in the county of Guyahoga and State of Ohio, have invented certain new and useful Improvements in Electric Lamps; and I do hereby declare the following' to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanyingdrawings, which form part of this speciiication.

My invention relates to improvements in electric-light regulators, and it consists in the devices and appliances hereinafter set forth and claimed.

In the drawings, Figure 1 represents one form of my device as embodied in a lamp adapted for a to-and-fro current. Fig. 2 is a detached view, showing, in detail, my elongate-l plunger for use in the dash-pot, also showing its valvularconstruction. Fig. 3 isa detached plan view of the arm or lever E. Fig'. 3 is a perspective view ofthe same device. liig. il shows a modiiied arrangement of the heating wire or bar il. Fig. 5 shows the wire il surrounded by the heating-spiral. Fig. 6 represents,in three views-wiz., side elevation and two developed views-a modified arrangement of the elements Ml, in which my compensating principle is preserved. Figa? shows a inodiiication similar to Fig. G, except-ing that the compensating' principle is not introduced. Figs. S and 9 are diagramatic representations, showing a system of several regula-tors having an induction apparatus and operated by a single current. Figs. 10 and 11 represent a lamp according to my invention adapted for use' with a continuous current.

In Fig'. l, K is a base, of suitable material, to which are attached two metallic rods, a I), supporting a cross-piece of wood, K. A carbon-holder, L,is attached to the base K, and carries the carbon F. This carbon-holderis electrically connected with the rod a, which latter carries a binding-post, N, at its upper end.

A l are metallic frames for supporting and containing the mechanism of the regulator, and are attached to the cross-piece K'. Gis a tube of metal, closed at its lower end, and provided with a carbon-holder, L', in which is placed the carbon F. The upper end of the tube G is enlarged, as shown. The tube C moves up and down freely through two bearings, one in the frame A, and the other attached to the cross-piece K', as shown. d is a piston, iittin g freelyin the tube G, and attached to the frame B by means of the rod or linl; c.

Fig. 2 shows the piston d enlarged. It is quite long, as compared with its diameter, is hollow the greater part of its length, and is provided at its upper end with several small openings, which are closed by a ring or washer fitting loosely on the rod which carries the piston. Thus the piston is provided with a valve opening upward.

In operation, the tube C, Fig. 1, is partly iilled with glycerine or other suitable liquid, and then, with the piston d, forms a combined carbon-holder iod and dash-pot.

Owing to the valve d in the piston d, the tube C may be pushed upward freely, but by the closing of this valve when a downward movement is commenced, the motion is greatly retarded, the rate of movement beingl determined by the rapidity of leakage of the glycerine past the piston d. This piston being made long, as before explained, renders the leakage very gradual, even when the piston does not tit very closely in the tube. Thus the descent of the tube C is very gradual, while its upward movement is free.

The valve d in the piston l may be dispensed with, thus retarding both upward and downward movement of the tube U 5 but this is inconvenient when putting new carbons in the holder L', and is otherwise objectionable.

If the rod C is forcibly drawn down for any reason, a vacuum will be formed under the piston d, and the glycerine above the piston might overflow the tube, were it not for the enlargement of the latter at its upper end. This enlargement affords a rese 1voir for hold.- ing the glycerine in the case, as above described.

E, Fig. 1, is an arm or lever, of metal, provided at one end with a cylindrical crosspiece, of steel or other suitable material, j', as shown in plan in Figz. The projecting ends of this cross-piece are formed into blunt knife-edges, as shown.

A wire, 'i il, of suitable size, and preferably of soft steel, is passed through a small holein the central, part of the cross-piece or fulerum f, and each half of the wire is then passed once or twice around theP cylindrical portion of the cross-piece in opposite directions. The ends of this Wire are then carried up and attached to the studs g g', as shown in Fig. 1. These 'studs are threaded, and provided with nuts above the frameB, as shown. The stud y is insulated from the frame B by means of a suitable bushing in the hole through which it passes, but is electrically connected with the binding-post P.

H is a very stiff. spring, of steel or other metal, attached to the frame A, and split at its free end, so as to engage with and form a support for the knife-edges at the extremities of the fulcrum f. The wires i rl, being sufliciently strained by means of the screwstuds g g', hold the lever E firmly against the spring H, and in the position shown in the ligure.

D is a rin g-clamp or washer surroundingthe tube C, and adapted to clamp andslift thelatter when one side of the clamp is raised. h is a liftin g-lin ger pivoted to the lever E,and adapted to lift the washer D when thefree end ofthe lever E is raised. a is a iiexible metallic connection between the lever E and frame A.

When the binding-posts l? N are connected with a suitable source of electric current the v path followed by said current will be as folcylindrical portion of the fulcrum f, being partia-lly relieved of its support on one side, will be carried downward by the .powerful spring H, th'e free end of the lever E will be raised, and with it the lifting-finger h, clamp D,.tube C, and carbon F', thus establishing the electric light between the carbons.

The amount of separation between the carbons may be adjusted by varying the relative tension of the'wires t' t" by means of the screwstuds g g.

As the carbons burn away the current will diminish, owing to t-he increased resistance of the voltaic arc; the wire r11 will become less hot, and will accordingly contract. The free end of the lever E will descend, and the carbon F will move down ward unt-il the increased current caused thereby expands the wire t and checks the movement. `When the clamp D reaches the frame A under it, it will allow the tube C to slide through it until the'increased current, due to the approach of the carbons, causes the washer D to again clamp andretain the tube C.

It will now be seen why the dash-pot arrangement of the tube Gis provided; for if this provision were not made the tube G, being once released by the clamp D, would force the earbons' entirely together before the clamping device could have time to act. The slow downaccident.

A notable feature of my invention, as above described, is the use of two wires, t' il, of the same metal. This feature I style my compensatin g device.77 It insures the normal workingof the apparatus at all temperatures, since it is the difference in temperature between the wiresizl, and not the actual temperature of t1, which determines the working ofthe apparatus.`

In practice, the wires yi t" are from fifteen to twenty inches long, and a difference in temperature between them of 2000 Fahrenheit is ordinarily sufficient to operate the device. In ordinary workin g the temperature of the whole apparatus gradually rises considerably, and, of course, the absolute temperature of the wire t" auginents accordingly, and were it not for my. compensating device the operation of the regulator would be seriously affected.

Fig. 4 shows one of several forms of device in which but one wire, t", is employed. This device will obviously perform all the functions described in connection with Fig. l, except compensation for changes of general temperature.

The wires 'L' 'il may be replaced by thin ribbons of metal, and this is even desirable, so far as that portion which passes around the fulcrum f is concerned, on account of greater iiexibility; or this part may be ribbon and the rest wire.

The wire t may be surrounded by a long helix, through which the current passes, while being itself insulatedv from the current, and thus be heated indirectly by the latter. Fig. 5 shows such a modification.

Instead of employing wires t' i1, as in- Fig.1, I may use narrow sheets of metal connected rigidly together, side by side, and insulated from each other both thermally and electrically.

The'pair may be used straight, curved, or.

coiled, a's in Fig. 6, which shows this form of my invention. Here the expansion of the inner strip of metal, i, by the heat due to the passage of current through it, while the outer strip, t', remains unheated, operates to raise the lifting-iingcr h. This arrangement of parts evidently embodies my compensating device,

and is a mere modified form 'thereetl Fig. 7 shows a device similar to Fig.'6but the strips of metal i i2 are of different metals, expanding unequally on the application of heat. the metal 'il being the more expansible of the two, and are both heated either by the passage of current through them, or by the passage of` current through a helix surrounding them, as shown in the figure.

The operation of the device is evident, but it lacks the compensating feature, which was retained in the device shown in Fig. 6.

My invention, so far as described, is equally useful with rapidly intermittent, alternating,

They are riveted or soldered together,

or continuous currents; but it is especially adapted for alternating currents where magnetregulators are not available.

Vhen two or more regulators, such as I have described, are operated in a single circuit, conveying an alternating current, they will work irregularly, the same as other regulators of ordinary t'orm wit-h a continuons current. The

reason for this irregularityY ol" action is fully explained in Letters Patent No. 212,183, granted to me February 1 1, 1879.

In my present device I correct this irregularity ot' action by means of the adjustinghelix I, Fig. 1. The ultimate eiiect ot' this helix in my presentdevice is the same'as that ot' the adjusting-helix I, described in the Letters Patent above referred to; but its operation is entirely dit't'erent.

The helix I, Fig. 1, is composed of many convolutions of line wire, the ends ot which are connected respectively with the binding-post N, and, through the stud g and its connections, with the binding-post I). Thus the helix forms aconstantly-closed circuit between the binding-posts I) N. Two passages arethusattorded "to the current through the regulator-011e otl comparatively low resistance through the carbons, Snc., the other ot comparatively high resistance through the helix I-the amount of current passing through each channel being inversely asits actual resistance, but the actual resistance of the helix I is much greater for rapidly-alternating currents than for continuous currents, owing to the inductive action of each convolution of the current on its neighbors in the former case. This disturbing element must be considered when calcnlatingthe dimensions ot' the helix.

The helix is wound on an insulating-spool, which yery loosely surrounds the wire i, which, in this case, is made otiron or steel.

Now, when the regulator is operated by a rapidly-alternating electric current, magnetism oi' rapidly-alternating polarity will be induced in the wire i, which will thus become heated to a certain extent.

The number oi" convolutions oi' the helix I and its actual resista-nee are so arranged that the heat developed bythe alternating magnetism in the wire if shall be less than the heat developed in the wire i1 by the passage ot' the main current through it when the voltaic arc between thecarbonsis ot'normal length. Here, as formerly, the dii't'erence in temperature between the wires 17121 determines the operation of the regulator.

Suppose, now, that the carbons burn away until they are more than their normal distance apart, the current will not be materially lessened when several regulators are in circuit, and the wire i1 will maintain its temperature, thus holding the carbons apart, but, owing to the increased resistance ofthe voltaic arc, more current will be shunted through the helix I, the alternating magnetism ofthe wire 'i will be increased, and consequently its temperature. This is equivalent to a reduction of temperature in the wire i1, and the carbon F is allowed to move downward. On the other hand, it the earbons approach too near together less current will pass through the helix, the wire i will become cooler', which is equivalent to au increase ol tem perature in the wire i1, and the carbon will be separated. Thus, by means ot" the adjusting heating-helix I, any number of these regulators may be operated uniformly on a single suitable alternating current.

Vhen a large number of regulators ot' any kind are operated directly by a single elect-ric current, the danger otl extinguishing all. by breaking the circuit in any one is considerable, and in view ot' this fact I shall brietly, and in a general way, refer to a method for correcting this objectionable feature. It is my purpose, however, soon to apply for separate Letters Patent upon the system, or what may be termed the inductive method,77 which I shall presentlyret'er to, and therefore I do not waive, on account ot what l shall now describe, any right to a subsequent application for patent upon such device or method. By combining my expansion-regulator7 (as I have styled the one above described) with a suitable form of dynamic induction apparatus, and using' a rapidly-alternating current, I avoid this danger, since in this case the main circuit through which the current passes is unbroken under all circumstances.

Figs. S and 9 ot' the drawings showin a diagramatic manner a battery, or preferably a dynamo-electric machine, Z, designed to maintain a current through the circuit Z1. It is commonly the practice to cut the circuit Z1 and introduce into it one or more electric lamps, in such a manner that the current through said circuit Z1 shall pass through and directly operate them. Instead ot' so doing, however, I propose, if desired, to operate the lamps by an induced current due to and generated by the current oli the circuit Z1.

I shall not here specity any particular electro-induction apparatus, reserving such a description for a proposed subsequent application, as above stated.

It is well known that when an electric current is started iu one otl two parallel and adjacent conductors an inverse current is induced in the other conductor, lasting only until the imlucing-current has obtained its maximum strength; and that when theinducing-cinrent is stopped or diminished a direct current is induced in the neighboring conductor. I propose to utilize these lacts in the construction of my induction apparatus alluded to, whereby a current through the circuit Z1 will set up an induced current in each circuit Z2 of an elec tric lamp, Z3, as diagramatically illustrated in Figs. S and S). By such an arrangement and system as just intimated, and as suggested in Figs. S and E) ot' the drawings, several lights might be operated upon a single circuit, and the removal or extinguishing ot any one or more from any cause whatever would not materially aiect the operation of any other lamp to-and-lro-current type of lamp.

that might be operated by the current through the circuit Zl.

Having now, for the purposes of the present specification, suiiiciently alluded to the induction system suggested in Figs. 8 and 9 of the drawings, and having hereinbefore alluded to the fact that my invention isy equally applicable to lamps employing a to-and-fro, a pulsating, or a constant current, I shall now briefly explain how my invention may be embodied 'in a lamp suitable for a continuous current operating more than one lamp; and for this purpose I have shown two forms of device in Figs. 10 and 1l of the drawings.

In Fig. 10 the wire il is placed in the general circuit, and' is made of sufficiently high resistance to bevheated by the current operat- .ing the lamp, and the difference in temperature between the wires i il andthe consequent diii'erence in expansion and length of said wires, as before pointed out, is the direct means whereby thelifter D is moved.

In the form of lamp shown in Fig. 10, I is an adjusting-helix, which is always in closed circuit, and the amount of current'passin g through it is always regulated. by the resistance of the voltaic arc-that is, it' the voltaic arc becomes too long, and thereby ol'ers an abnormally great resistance, the current is increased through the helix I, and vice versa, as already explained in Fig. 1. This helix is made to attract an armature, I', which is pivoted to the lamp and electrically connected with the general circuit.

i2 is a branch wire from the wire i', and it is made to terminate just above the armature Il as it rests iu its open-circuit position.

The operation of the device, as just described and shown in Fig. 10, will be as follows: The difference in tension between the wires i and il, due to the heating of the wire il by the current operating` the lamp, will act to raise the lifter D, as already specified, in the So long as the voltaic arc does not offer any abnormally great resistance, theparts will be substantially in the relative positions shown in the drawings, Fig. 10, but when, for any reason, it is necessary that the lamp should feed, or that the lifter D should descend, or the wire il made cooler, such a necessity will result .in a condition of things that will cause an increased currentythrough the helix, suicient to draw up the armature I until itcomesinto electrical contact with the branch wire i2. This will greatly diminish the current passing through the wire il, and its heat will be consequently and correspondingly decreased, and this will result in a re-establishmcnt of normal relation between the carbons and other parts to put the lamp again in proper operation. And now, the current having a suiiiciently free passage through the carbons, the magnetism of the helix I'will be so weakened that the armature I will be released, and break the circuit through the branch i2, and now the current passing through the wire il will again heat it. This operation is manifestly equivalent to cooling the wire i, as it is the r lative temperatures of the wires i andv il that ,determine their relative tension,

and, consequ intly, their lifting action upon the carbon-separ ting apparatus. y

I have, in Fig. 10, shown how the wire il may be cooled by automatically shunting its heatingcurrent from it as necessary. This function or equivalent is susceptible of being performed in a variety of ways-as, for iustance, by any arrangement such as the interposition between the armature I and branch wires i2 of a variable resistance, governed by the condition of the voltaic arc and the resulting magnetism of the helix I; or the heat ofthe wire il may be governed by purely mcchanical contrivance, and one such arrangement is shown in Fig. 11, where the wire il is surrounded by a tube.

The relative positionsof the wires i il, Fig. 11, are modified as shown merely for convenience in locating and applying the tube i3. This tube i3, in the form shown inthe drawings, is held, stationary in the frame of the lamp, and is closed at its bottom by any suitable valve arrangement operated by a magnetlever, which is moved by the attractive force of the helix I. Now, as the wire il needs cooling for purposes before pointed out, the current through the helix I will be sucient to' draw up the magnet and open the valve at the bottom of the tube il', thus admitting air into said tube, and allowing the inclosed wire il to cool, for when the tube i3 is closed the loss ,of heat from the wire il is greatly impeded, and a given amount of current will more rapidly and intensely heat it than though it were freely exposed to the air. Thus, by governing the circulation of air around the wire il in any manner, its temperature may be controlled so as to insure a proper operation of the lifter D according to the varying conditions of the voltaic aro.

When the character of the current operating the lamp is such that the wire il, in order to be sufficiently heated, is too small to be of suicient strength, one or more similar wires may be added to it, so connected with other parts of the apparatus that the current shall pass through them successively. Thus the strength of as many wires as may be necessary will be secured. v l A As respects the heating of the wires i or il, or their equivalent, I do not limit myself, as my invention consists in any appropriate method of accomplishing this heating, which might be accomplished by a shunt-current, either constant, pulsating, or alternating, or

by the adjusting-helix, as shown, orA by a variety of other methods, nor do I limit myself 4 l to any specific method of controlling the n1ove` ment of the carbon rod or holder G by a dashpot or' equivalent contrivance. This may be effected by making the carbon-holder itself the cylinder of the dash-pot, as shown inFig.` 1 of the drawings; or, as shown in Figs. 12, 13, and 14, thecarbon-holder may have a snfteiently slow and steady movementby any suitable connection with a dash-pot placed adjacent to it.

Fig. l2 of the drawings illustrates one method where a carbon or carbon-holder, L, is connected with a dash-pot, G d, bya belt-andpulley arrangement. Fig. 13 illustrates the same arrangement, where a pulley might be dispensed with; and Fig. M represents a beltand-pulley connection between dash-pot and carbon, wherein a dash-pot of a shorter length than in the forms shown in Figs. l2 and 13 might be used.

l. ln combination with the wires t' il, or their equivalent, an adjusting-helix, I, or its equivalent, through the iniiuence of which the wires '1T fil are maintained at suitably diiierent temperatures, substantially as and lor the purposes described.

2. In an electric lamp wherein the carbonmoving apparatus is actuated by the expansive action otheat upon some portion of said apparatus, the wires 'i and il, or their equivalents, adapted, as required for the varying conditions for maintaining a continuous and steady light, to be ditterently heated7 said difference ot heating automatically caused and controlled substantially as and for the purposes described.

3. An electric lamp wherein the separation and government of the carbons are effected by reason of the difference in temperature between the wires fi il, or their equivalent, sub stantially as and for the purposes described.

d. In an electric lamp, the combination, with a moving carbon or its holder, of a clamp constructed to grasp and move said carbon or carbon-holder, and, in connection with said clamp', suitable mechanism adapted to be set in motion or controlled by the expansive et'- fect of heat generated by the electric current operating' the lamp, substantially as shown.

5. In an electric lamp, the combination, with a moving carbon-holder, of a tube, C, said tube constituting the body or cylinder and a moving element of the dash-pot, substantially as shown.

In testimony whereof l have signed my name to this speeilication in the presence of two subscribing witnesses.

CHARLES F. BRUSH.

Vitnesses LEVERETT L. Lneen'r'r, JN0. GRowELL, Jr. 

